/*
 * Copyright 2019 成都深地领航能源科技有限公司. All rights reserved.
 * PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sdlh.demo.stream;

import java.util.Scanner;

/**
 * @author 成都深地领航能源科技有限公司
 */
public class StrDemo {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        String line = input.nextLine();
        if (null == line && line.length() > 100)
            return;
        String str = String.valueOf(line.charAt(0));
        for (int i = 0; i < line.length(); i++) {
            if (!str.contains(String.valueOf(line.charAt(i))))
                str += line.charAt(i);
        }
        System.out.println(str);
    }
}
